:root{--background-color:#f7f9fc;--card-background:#ffffff;--text-color:#2c3e50;--primary-color:#3498db;--secondary-color:#e74c3c;--border-radius:8px;--box-shadow:0 4px 6px rgba(0,0,0,0.1)}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif;background-color:var(--background-color);color:var(--text-color);margin:0;padding:0}.container{display:flex;min-height:100vh}.sidebar{width:250px;background-color:var(--card-background);box-shadow:var(--box-shadow);padding:2rem;display:flex;flex-direction:column;gap:1rem}.main-content{flex-grow:1;padding:2rem}.filter-button{width:100%;padding:10px;border:none;border-radius:var(--border-radius);background-color:#ecf0f1;color:var(--text-color);cursor:pointer;font-size:1rem;transition:background-color .2s ease-in-out}.filter-button:hover{background-color:#bdc3c7}.filter-button.active{background-color:var(--primary-color);color:#ffffff}.groupbuy-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:1.5rem}.groupbuy-card{background-color:var(--card-background);border-radius:var(--border-radius);box-shadow:var(--box-shadow);overflow:hidden;text-decoration:none;color:inherit;transition:transform .2s ease-in-out}.groupbuy-card:hover{transform:translateY(-5px)}.card-image-container{position:relative;width:100%;padding-top:66.67%;overflow:hidden}.card-image{position:absolute;top:0;left:0;width:100%;height:100%;object-fit:cover}.card-content{padding:1rem}.card-title{font-size:1.25rem;font-weight:700;margin-bottom:.5rem;word-break:break-word}.card-dates{font-size:.9rem;color:#7f8c8d}.detailed-page{max-width:800px;margin:0 auto;padding:2rem;background-color:var(--card-background);border-radius:var(--border-radius);box-shadow:var(--box-shadow)}.detailed-image-container{width:100%;height:auto;margin-bottom:1.5rem}.detailed-image{width:100%;height:auto;object-fit:contain;border-radius:var(--border-radius)}.detailed-title{font-size:2rem;font-weight:700;margin-bottom:1rem}.detailed-section{margin-bottom:1.5rem}.detailed-heading{font-size:1.2rem;font-weight:700;color:var(--primary-color);margin-bottom:.5rem}.detailed-text{line-height:1.6}.detailed-link{color:var(--primary-color);text-decoration:none;font-weight:700}.detailed-link:hover{text-decoration:underline}